1. Field of the Invention
The present invention is directed to the field of reset circuits for use with microcomputers and more specifically to the area to reset circuits that provide an inhibiting reset signal to a microcomputer when power source voltage drops below a safe level.
2. Description of the Prior Art
It is well known that microcomputers operating from regulated power supplies must be inhibited during both the power-up phase and in the event that the DC power to the regulated power supply is interrupted or drops below a predetermined level.
Prior art circuits such as those shown in U.S. Pat. No. 4,367,423 provide complicated circuits that generate reset signals for a microprocessor during the time the circuit is initially powered up or when the unregulated source voltage drops below a preselected level. Generally such prior art circuits are expensive and constitute a significant drain on a battery source.
The primary objective of people working in this area is to find a low cost solution to achieving the desired functions.